The long-term goal of this research program is to define the structure, metabolism, and function of proteoglycans as they occur in normal and diseased connective tissue. The biochemical processes associated with 1) the endocytosis of lysosomal enzymes carrying the phosphomannosyl recognition marker; 2) the intracellular translocation of newly synthesized lysosomal enzymes as mediated by a specific membrane-associated phosphomannosyl receptor; and 3) the uptake of proteoglycans as mediated by recognition markers by cultured normal and mutant cells are currently under investigation.